Electronic fuses, such as for example the electronic fuse disclosed in U.S. Pat. No. 8,050,005, may comprise a current shunt and a controlled switch. The voltage drop over the current shunt is sensed by a comparator and is proportional to the current flowing through the current shunt. The trip value of the electronic fuse is selected by selecting a specific voltage of the comparator. In a preferred embodiment the controlled switch is a MOS transistor with low on-resistance. The use of electronic fuses is steadily increasing due to the possibility to tailor and control the electronic fuses. It is today common to include electronic fuses directly on a circuit board close to the power consumer.
Yet another solution is disclosed and outlined in a conference paper by Klaus Rambold, “Power distribution to provide reliable function of DC/DC converters” (ISBN 0-7803-3996-7). This solution discloses the use of electronic fuses as additional means to improve system behaviour, such as for example during hot swapping of circuit boards that causes large inrush current during start-up.
In order to provide a fuse box that utilizes electronic fuses, a number of solutions are available in the art. The disclosed systems are unflexible and unexpandable with a fixed number of fused outputs, which causes a lot of unused outputs as well as unnecessary energy consumption. Not to mention the associated costs of using unnecessary complex circuits.
There is therefore a need for an improved system of electronic fuses that overcome the above mentioned problems associated with existing solutions.